Oysters are experiencing a renaissance in the United States as a new dining trend. This guide provides some basic information about oysters including their biology, their growth methods, and their industry.
3. Edible Oysters
7 commercially edible oyster species
◦ Eastern Oyster -- Crassostrea virginica
◦ Pacific Oyster -- Crassostrea gigas
◦ Kumamoto Oyster -- Crassostrea sikamea
◦ Belon Oyster -- Ostrea edulis
◦ Olympia Oysters -- Ostrea lurida or Ostera conchapila
◦ Portuguese Oysters – Crassostrea angulata
◦ Sydney Rock Oysters -- Saccostrea glomerata
*Not the same as pearl oysters
Available at Pangea
4. About the Edible Oyster
Scientific Classification
◦ Animalia > Mollusca > Bivalvia
Anatomy
◦ Filter feeders
◦ Feeds on plankton & algae in water
◦ Can filter up to 1 gallon an hour
◦ Abductor muscle keeps shell closed
◦ Hermaphrodites
◦ Change sex depending on life stage and season
◦ Spawn during the summer
◦ Triggered by water temperature
◦ Can release up to 100 million eggs per female
5.
6. Oyster Aquaculture
Sustainable source of seafood
◦ Oysters are farmed in the ocean, its natural habitat
Wild oysters are limited
◦ Overfishing led to dwindling numbers e.g. Chesapeake Bay
◦ Wild fisheries only open seasonally
◦ Regulations on catch limits and harvest periods
2013 NOAA Fisheries report valued landings at $218 million
◦ Pacific region leads in production
◦ Industry could be much larger since report
Wild vs. farmed oysters
◦ Each has own advantages and not necessarily better than the other
7. Farming Oysters
1. Growers buy seed (juvenile oysters) from hatcheries
◦ Seed can be purchased at different sizes
◦ Some growers collect wild spat to cultivate
2. Seed is nurtured and tended until it reaches market size
◦ Typical market size for Eastern oyster ~3”
◦ Market size for Pacific oyster varies
3. Grade and cull oysters for size and quality
4. Clean, bag, and ship to distributors and restaurants
8. Growout Methods
Growout methods greatly influence
look and even taste
◦ Methods vary depending on the
local environment
The Shigoku is a Pacific Oyster like the ones on
the right, but because it has a different growout
method, the look and shape is very different.
9. Growout Methods
Bottom-culture
◦ Oysters grow out on the ocean bottom
◦ Natural growout like wild oysters
◦ Advantages: produces hearty and strong shells
◦ Disadvantages: losses due to suffocation, predation, weather, etc.
Off-bottom culture
◦ Oysters never touch the ocean bottom
◦ Advantages: keeps oysters protected and no losses
◦ Disadvantages: weak shell growth
10. Off-bottom Methods
Cage-cultured Tray-cultured Rack-and-bag
Surface-culture (i.e. bags or trays
float on water surface)
Suspended-culture (i.e. bags or
trays hang or suspended in the
ocean)
11. Growing Process on Standish Shore Oyster Farm
DUXBURY, MASSACHUSETTS, USA
12.
13. Every May, we buy
about 3 million oyster
seed graded at 2mm.
14. We place the seed in
our upweller, a nursery
system that pumps
plankton-rich water
through each silo to
“force-feed” the
oysters. The oysters
should double in
volume every few days.
15. The oysters are graded
for the first time at
6mm. Once they reach
this size, they continue
to grow in bags and
cages out in the bay.
16. During their growth
period throughout the
summer, the oysters
are tumbled to
promote consistent and
strong shells. Our
tumbler also grades the
oysters with the holes
in its metal screens.
17. In the fall, the oysters reach
1.5-2.5” and are ready for
winter hibernation. No new
growth occurs in the winter.
Some growers store their
oysters in coolers or long
line them to the ocean
bottom. In Duxbury, many
bottom-plant their oysters
and hope they will survive
through the winter.
19. When the oysters are
ready the following fall,
we harvest them by hand
picking, raking, or
dragging a rake across the
bottom with a boat.
20. In its final stages, the
oysters are hand culled
for quality and size,
purged on the farm to
spit out any mud, and
bagged to be sold!
21. Industry Trends
Oysters are experiencing a renaissance
◦ Used to be cheap and eaten by working class
◦ Oyster market becoming the wine market
◦ “Terroir” to wine as “merroir” is to oysters
◦ Marketing and branding allowing more niche players
◦ Raw bars opening across the country
Farm-to-table movement
◦ Emergence of small local oyster farms
◦ Rise in consumer interest – e.g. oyster farm tours
A new loss leader in restaurants
◦ Draw customers in with oyster happy hours and make margin on drinks
◦ Restaurants feel the urge to jump on the bandwagon
22. Industry Concerns
Growing oyster consumption also means more shellfish illnesses
◦ Vibrio parahaemolyticus
◦ Bacteria that lives in the ocean
◦ Causes illness when high amounts are consumed
◦ Multiplies in warm conditions
◦ Regulations burden smaller farms
Mislabeling and seafood fraud
Environmental Impacts
◦ Water acidification and environmental changes
◦ Algae blooms, red tides, and closures put pressure on supply especially in summer
◦ Gulf oysters affected by BP oil spill
◦ Chesapeake still recovering from overfishing
◦ Oyster farming is becoming more industrial
◦ http://www.seattletimes.com/seattle-news/environment/dept-of-ecology-growers-cancel-pesticide-permit-affecting-oysters-2/
23. For more information…
Contact Us
Pangea Shellfish Company
314 Northern Avenue
Boston, MA 02210
(617) 439-4999
sales@pangeashellfish.com
Visit our website at www.pangeashellfish.com or sign up for our
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Notes de l'éditeur
Tumbling
Chisels shell to promote uniform and strong shell growth
Cage-culture
Rack-and-bag-culture
Surface-culture: trays or bags float on water surface
Suspended-culture: trays or bags suspend/hang from a line